Preparation And Properties Of Non-isocyanate Polyurethane Based On Cardanol

This article combined the natural product cashew phenol extracted from the cashew shell oil with the cyclophosphonitrile,then the greenhouse gas CO₂ was immobilized in the structure.A series of bio-based non-isocyanate polyurethane NIPUs were prepared by the reaction of cyclic carbonate and amino group.The mechanical properties,surface properties,thermal properties and solvent swelling properties of these materials were studied.Firstly,six-arm-branched cyclophosphonitrile EHCPP1-6,EHCPP2-6 and EHCPP3-6 with different epoxy values were synthesized from six-arm-branched cashew phenolic cyclophosphonitrile HCPP by the epoxidation reaction with metachloroperbenzoic acid system.Cyclic carbonate was synthesized by fixing carbon dioxide on EHCPP to form the corresponding carbonated bio-based intermediates CHCPP1-6,CHCPP2-6 and CHCPP3-6.And then the three-step method was used to synthesize three kinds of biological based diamines FA-a,FA-b and FA-c as small molecular curing agent.A series of NIPUs products were synthesized by thermal curing of cashew phenolic cyclocarbonate and furfural-based diamine.All the compounds were characterized by NMR and FT-IR,and the curing conditions were investigated by FT-IR and gel content testing.The study of the properties of NIPUs showed that the gel content increased alone with the solubility of three kinds of diamine curing agents FA-a,FA-b and FA-c in CHCPP,the lowest gel content was 77.8% of PU1-6a,the highest was 97.3% of PU3-6c.And all of the NIPUs were surface hydrophobic.The maximum elongation at break was 41.29% of PU1-6a and the lowest was 7.77% of PU3-6c.On the contrary,corresponding elastic modulus were 0.13 MPa and 380.22 MPa which increased alone with the gel contents.The lowest glass state temperature was 6.1℃ and the highest was 60.5℃.The initial decomposition temperatures T5% were concentrated in the range of 248.8-276.8℃,and the maximum decomposition rate temperatures Tmax1 and Tmax2 were 295.7-344.5℃ and 427.0-448.1℃,respectively.The theoretical limit oxygen indexes of the 9 kinds of NIPUs were within the range of 22-27.The water-swelling properties and the toluene-swelling properties of materials decreased alone with the increase of the gel contents,and the ranges finally reached 2.1%-19.1% and 40.3%-149% after 15 d.The water absorbability increased slowly,and the absorption of toluene increased first and then decreases until reached fixed values.